Overheating coolant

[Ranger16]

You are terribly misinformed. In addition to a quick warm up, they maintain engine temperature at or near the stated thermostat temperature.

 

[Bigal75]

I should have worded better...It keeps a minimum temp. It does not prevent the engine from getting hotter. The most efficient way to cool is to pass as much coolant as possible from the engine to the radiator as quickly as possible.

 

[Ranger16]

Again you are misinformed. Pass it too quickly and it has less time to transfer heat.

https://www.2carpros.com/articles/how-an-engine-thermostat-works
"Avoid running an engine without a thermostat, this unit also acts as a system flow regulator, if coolant is allowed to travel too fast in the system, the heat exchange rate is reduced in the radiator and the engine will overheat. "

http://www.stant.com/index.php/english/products/consumer-products/thermostats/abcs-thermostats/
"An engine should never be operated without a thermostat, even in extreme temperatures"

https://en.wikipedia.org/wiki/Wax_thermostatic_element
"Once the optimum operating temperature is reached, the thermostat progressively increases or decreases its opening in response to temperature changes, dynamically balancing the coolant recirculation flow and coolant flow to the radiator to maintain the engine temperature in the optimum range as engine heat output,"

"Under normal operating conditions the thermostat is open to about half of its stroke travel, so that it can open further or reduce its opening to react to changes in operating conditions. A correctly designed thermostat will never be fully open or fully closed while the engine is operating normally, or overheating or overcooling would occur."

 

[Bigal75]

I quoted this from another site. I'm not getting into a pissing match here.


Removing the thermostat will make the car run cooler... You can't run coolant through a radiator too fast.

First Law of Thermodynamics...

Q=mc(deltaT)

Q = heat removed
m = flow of coolant
c = specific heat capacity of coolant
deltaT = change in temperature of coolant in to coolant out

Using this equation, the faster coolant flows through a radiator, more heat will be exchanged.

 

[Bigal75]

Also...

The Stewart Components Website states:

A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However the cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot spots", which can lead to failures.

Years ago, cars used low pressure radiator caps with upright-style radiators. At high RPM, the water pump pressure would overcome the radiator cap's rating and force coolant out, resulting in an overheated engine. Many enthusiasts mistakenly believed that these situations were caused because the coolant was flowing through the radiator so quickly, that it did not have time to cool. Using restrictors or slowing water pump speed prevented the coolant from being forced out, and allowed the engine to run cooler. However, cars built in the past thirty years have used cross flow radiators that position the radiator cap on the low pressure (suction) side of the system. This type of system does not subject the radiator cap to pressure from the water pump, so it benefits from maximizing coolant flow, not restricting it.

 

[bigmanjbmopar]

What's boil over and pressure? LMAO

Main reasons I run with Evans waterless.

 

[RedBeard]

Fortunately it was the thermostat. I installed the thermostat on the left 4 years ago, I think it was a mr gasket 180 degree I think it was the one for 25 bucks. I boiled them up on the stove and the left one stayed closed while the right one (new stant 180F) opened. Not sure if it just failed or got plugged up with rust but it is not usable. I like the stant design, simple is good. So the boilovers were coming from the block getting superheated with no coolant flow.

I popped off thermostat housing expecting to have coolant fall out but it was bone dry from boiling with signs of corrosion. I took the thermostat out and bolted back up without a t-stat, ran about 20 miles on the highway and around town. Took a long time for the engine to get to operating temp as expected but once it did it stayed at 180F and didnt move. Heads, water pump, radiator, all 180F. With the old thermostat the water temp would bounce between 180-220. I'm tempted to run without a thermostat because it runs so cool, it doesnt run quite as well that cold probably will need to retune. For now I'm going to get the system flushed out and install the stant.

View attachment 352352

Having the same issue of 383 overheating. Checked flow with cap off radiator, no signs of circulation. Cap on, let engine warm up, no pressure in upper hose. Stuck thermostat??? Ordered a 180 thermostat, picking up today. Since I have to deal with the antifreeze, going to flush the system after install of new 180. Hopefully that is it, otherwise changing out the water pump.

 

[threewood]

I wouldn't even use a Mr. Gasket sticker if it was free let alone a componet critical to the engine. Regular Stant thermostat is proven.

 

[wyrmrider]

Robertshaw made the best thermostats
try and find thermostat for 413 motorhome

 

[Billccm]

For whatever reason mopar muscle magazine always uses a miloden 180.

Btw, I've had good luck with Mr Gasket spark plug wire separators.

 

[MoparLeo]

Remember to use always Distilled water to get your 50% mix.

 

[WileE]

I quoted this from another site. I'm not getting into a pissing match here.


Removing the thermostat will make the car run cooler... You can't run coolant through a radiator too fast.

First Law of Thermodynamics...

Q=mc(deltaT)

Q = heat removed
m = flow of coolant
c = specific heat capacity of coolant
deltaT = change in temperature of coolant in to coolant out

Using this equation, the faster coolant flows through a radiator, more heat will be exchanged.

Have you taken a course in thermodynamics ? For my degree, I have, and I'll explain why you're wrong. In simplistic terms. The heat of the coolant inside the radiator is conducted by the radiator. We're going to assume this as a constant. The coolant entering the radiator is 200 degrees. Since the heat conduction is a constant, if the flow is faster, the temperature of the coolant entering back into the engine is 150 degrees. If the coolant flow is slower,more conduction occurs, so the coolant temp returning into the engine is 100 degrees. The "cooler" coolant can absorb more heat in the engine ,since it's a lower temperature. That's why you have bigger radiators, thicker cores, it takes more time for the coolant to get from start to finish inside the radiator. Ergo, more heat conduction.

 

[SlinktRR]

Red beard, take the thermostat out and test it on the stove to verify whether it opens or not. Other possibilities are failing water pump or air trapped in the cooling passages.

 

[Photon440]

Have you taken a course in thermodynamics ? For my degree, I have, and I'll explain why you're wrong. In simplistic terms. The heat of the coolant inside the radiator is conducted by the radiator. We're going to assume this as a constant. The coolant entering the radiator is 200 degrees. Since the heat conduction is a constant, if the flow is faster, the temperature of the coolant entering back into the engine is 150 degrees. If the coolant flow is slower,more conduction occurs, so the coolant temp returning into the engine is 100 degrees. The "cooler" coolant can absorb more heat in the engine ,since it's a lower temperature. That's why you have bigger radiators, thicker cores, it takes more time for the coolant to get from start to finish inside the radiator. Ergo, more heat conduction.

One of the problems with this line of reasoning is that part of the equation is usually left out. True, slower coolant will come out of the radiator at a lower temperature. However the advantage of decreased restriction is increased volume. Even if a faster flow means that slightly less heat is pulled out as a gallon goes through the radiator, there are more of those gallons per minute and so resulting in a net increase in heat lost from the medium. I have to agree with Bigal75's post, as it includes the flow as part of the equation.

 

[WileE]

One of the problems with this line of reasoning is that part of the equation is usually left out. True, slower coolant will come out of the radiator at a lower temperature. However the advantage of decreased restriction is increased volume. Even if a faster flow means that slightly less heat is pulled out as a gallon goes through the radiator, there are more of those gallons per minute and so resulting in a net increase in heat lost from the medium. I have to agree with Bigal75's post, as it includes the flow as part of the equation.

Not when you have a thermostat as a regulatory device. The pump can only flow a certain volume. The reason for a larger radiator is for the coolant to spend more time for conductivity.

 

[bearman]

Food for thought always run heater system after working coolant this will help in getting rid of air pockets

 

[Johnpat]

Bottom hose may be collapsing internaly,does bottom hose have a spring in it????

 

[RedBeard]

Red beard, take the thermostat out and test it on the stove to verify whether it opens or not. Other possibilities are failing water pump or air trapped in the cooling passages.

Yep, but will just switch out thermostats since they are cheap. If that is not it then will deal with the other possibilities as you mentioned. Lower hose is fine, and my heater is bypassed. Was going to do the work this weekend but had to start moving things out of a house that I just flipped earlier than planned. Now also got some free $ to get a 66 Charger that has been sitting for about 20 years at a farm.

 

[SlinktRR]

Good deal, yeah with the shale boom in full effect the property values in ND must be favorable to sellers! I hope your cooling issues get solved with just the stat change. Stant for <$10 is a good one.

 

[RedBeard]

Thanks, me too. Our local car show is the first weekend of June.